Feed-water heater



2 Sheets-Sheet 1 J. F. SEBALD FEEDWATER HEATER Dec. 28, 1948.

Filed July 14, 1944 ATTORNEY Patented Dec. 28, 1494.8

2,457,605 FEED-WATER HEATER Joseph F. Sebald, Bloomfield, N. J., assignor to Worthington Pump and Machinery Corporation, Harrison, N. J., a corporation of Delaware Application July 14, 1944, Serial No. 544,889

6 Claims. 1

This invention relates to improvements in methods of and apparatus for heating and degasifying liquids, and more particularly to the use of high pressure' and temperature condensate (in addition to a normal supply of steam) in a multistage heating and deaerating apparatus for treating water for boiler feed purposes and other Serv ices requiring practically oxygen-free water.

The apparatus of the present invention is of the mixing type, as disclosed in U. S. Patents 2,308,719 and 2,308,721, both of which issued January 19, 1943, in contradistinction to the atomizing and tray types of water treating apparatus known in the art. The steam jet deaerators in accordance with the present invention and the foregoing patents embody two stages of heating and deaerating, the rst or primary stage consisting of a spray type direct contact heater and deaerator and the secondary stage consisting of a direct contact heater and deaerator of the steam jet eductor type. While the use of high pressure and tem perature condensate in the tray type of heating and deaerating apparatus presents few problems, the use of such condensate in apparatus' of the multistage type disclosed in the foregoing patents have presented certain dimculties not present in apparatus of the tray type.

In connection with the tray type, high pressure and temperature condensate is usually introduced into the heating and deaerating feedwater heater by a system of spray pipes between the lower portion of the heating element and the water level in the water storage compartment. The high pressure and temperature condensate is permitted to deaerate itself by partial flashing into steam, which steam is available for heating and deaerating the incoming feedwater. .The steam produced by flashing of the condensate is supplemented by the normal supply of steam from an exhaust system or other suitable source, except in Such cases wherein the heat balance is such that the quantity of flashed steam is sumclent to provide the necessary heat ,units for carrying out the heating process at a given pressure. Thus the construction of the "tray type deaerator is such that its performance will essentially be the same regardless of the source of steam supply; that is, from either the high pressure and temperature condensate, the exhaust steam or both. v

In a steam jet .deaerator incorporating a two stage heating and .deaerating structure, in accordance with the -foregoingpatents the introduction of high pressureand temperature condensate must be modiiled ifacceptable performance is to -be effected under all variations of source of steam supply. When the quantity of high pressure and temperature condensate is small in comparison with the total outlet capacity of the deaerator, it is customary to introduce this condensate into the apparatus directly into the primary heating and deaerating section (spray section). The steam liberated from this condensate short circuits or by-passes the second stage of direct contact heating and deaeration. If the quantity of this condensate is appreciable and the amount of flashed vapor approaches the normal requirements of the feedwater heater, the result is that only a small percentage of the effectiveness of the second stage of heating and deaeration is utilized.

Accordingly, an object of the present invention is to provide a steam jet deaerator embodying novel means for utilizing high pressure and temperature condensate for heating and deaerating purposes, in addition to a. normal supply of steam, wherein the construction is such that 'acceptable performance may be obtained under all variations of the source of steam supply.

A further object is to provide a, steam jet deaerator of the multistage heating and deaerating type wherein novel means are incorporated for utilizing high pressure and` temperature condensate for heating and deaerating purposes, inv addition to a normal supply of steam, and in which the high pressure and temperature condensate is introduced in such a manner as to maintain a balanced effectiveness of all stages of heating and deaerating under all variations of the source of steam supply.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a feedwater heater of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a vertical sectional view of a feedwater heater in accordance with the invention.

Figure 2 is a similar view of a modified form of feedwater heater.

Referring more particularly to the drawing, the feedwater heater and deaerator includesthe usual shell I, the ibottom portion of whichfprovides a storage space for storing the heated and deaerated water until it is removed for use, as indicated at 2. Treated water is removed from the storage throng vided for space through an opening 3 in the bottom 4 of the th a water inlet 8. a water outlet 1, and t ture condensate space ater to be treated is caused to ilow a ven 8. To the outlet I is connected a pipe 8 whic II. be eath the top I2 of the Shelli and is arranged cd centrically of the shell. Between the spray passes through the side III ot the shell I elivering water to be treated to a spray head 'Ihis spray head is positioned some distance 4 Y 38 having an inlet 81. The wall structure 35 is constricted at 38 to provide a narrow annular escape passage 38 about the upper end of the wall 32. Beyond the constriction 38, the wallA structure 35 is iiared to provide a scrubbing and conilned mixing chamber 40 arranged concentrically of the neck 28 and' beneath the wall 23. The lower end ofthe neck 28 is spaced from the perimeter of the upturned ilange28 to provide an annular escape passage 4I for the steam, which passage opens upwardly h ad II and the top I2 is mounted an annular 1 a d dished head or partition I3, with the cont c" vity of the partition facing downwardly. The i pa tition I3 is of smaller diameter than the wall I3 is positioned a slight distance below the top I2, the passage I4 places the spray chamber or I initial heating and deaerating space or compart- 1 ment I5 of the feed-water heater in com mmunication with the space I8A adjacent the top I2.

Water which enters the spray head Il' is sprayed through spring loaded valves or nozzles I8, of any approved type, into the initial heating and deaerating space I in the direction of the l partition I3.. The water emitted through the valves I5 contacts the steam in the initial heating and deaerating space I5 and is heated to approximately lsteam temperature. thereby partially deaerating or degasiiying the water.

The partition I3 is provided with a depending I0 and is arranged concentrically of the wall to provide an annular space or passage I4 between the partition and the wall. Since the partition 1 ange Il about its perimeter, which ange is arranged'concentrically with a water deilecting flange or partition I8 joined to the side I8 of the shell I. The partition I8 is provided with a central opening I3 and inclines downwardly. Water impinging against the partition I 3 falls o'n the partition I8 and into a collecting cone 20 'artition I8. This collecting cone includes spaced walls 2l, 22, and 23 so arranged as to provide a jacketed structure characterized by a conical space or chamber 24 for steam. 'I'he steam utilized for heating and deaerating the water, which steam may be derived from any suitable source` such as the exhaust steam from an engine, enters 1 the space 24 through an inlet 25 extending through the wall I0 and having communication with the space 24. Water which falls on the Acollecting cone 20 is further heated because of the steam circulating in the space 24. y

The water in the collecting cone 20, in its passage from the initial heating and deaerating stage to the second heating and deaerating stage,

drains therefrom through a downtake pipe 281 arranged concentrically of the cone. An annular and upturned ange 21 is formed at the lower i end of the downtake pipe 28, and a neck or pipe section 28 extends downwardly from the lower 40 ranged concentrically with and beneath the par- A cup-like member 3I is located beneath the downtake pipe 26 and includes an annular and upstanding wall 32 arranged concentrically ofI the ilange 21 but spaced therefrom to provide an annular escape passage 33 for water'delivered` to the compartment 34 deiined by the cup 3|. v

To the cup 3| is attached an annular wall structure 35 which is spaced from the wall 32 to into the cup 3l adjacent the passage 33, the iatter being arranged concentrically with the passage 38. Water collecting in the cup 3| is drawn up into the scrubbing and mixing chamber 48 by the eductor action of the steam from the passage 4I. The high velocity steam and water mixture impinges on the wall 23 and a baille 42, this spray being deflected 'by the baille 42 in a downward direction to the storage section 2. In addition to the steam and water mixture created bythe passages 33 and 4I, tlashed steam and condensate from the incoming high pressure and temperature condensate are admitted directly to the pas-- sage 39 for mixturewiththe normal steam and water mixture. 'I'hus the normal steam, water and a mixture of ashed steam and high pressure and temperature condensate pass through the constricted passage 43 `of the wall structure 35 in parallel iiow, this passage constituting a mixing or combining passage for the three streams.

Because of the constriction 38, the mixture made up of the steam, Water and ashed steam and high pressure and temperature `condensate is caused to :tlow at a high velocity through the passage 43 and enters the passage 40 of graduallyincreasing cross-sectional area in an upward direction, so that the mixture ows from an area of high velocity to a gradually increasing area. and reduced pressure. This results in further heating of the water to the temperature corresponding to the eilective steam pressure, which is higher than the steam pressure in vthe initial heating and deaerating'space I5. Only a small amount of the total steam is condensed in the space 43 since thev water is virtually at saturated temperature. This allows nearly full ilow of the steam to transmit suillcient velocity to the water to break it up into minute particlesand promotes the ilnal removal of oxygen and non-condensible gases. 4

Accordingly, the velocity v head of the steam and water mixture entering the space 48 is partially converted into pressure head, and the w existing in the storage section 2. As the water leaves the space'v43, a small amount of flashing occurs which further agitates the water particles and assists in-water and gas separation prior to impingement on the baille 42. The steam and non-condensible gases in the upward travel vfrom the second stage of heating and deaerating, break -through the water film deflected by the baille 42 mainder, together with the nori-condensible gases, breaks through the water spray therein and ilows upwardly through the space I4 and through provide an annular high pressure and tempera- ,75 a central opening 44 in the partition I3, into the rl. temperature is momentarily raised above t at.

spac'e I8, and into the inlet 45 leading to the vent condenser 5. The steam condensed in the vent condenser 5 is returned to the space I8 through the medium of a water sealed outlet l46, which condensate overflows the inlet and spills on the partition |3 for passage through the space |4 and onto the partition |8 for delivery to water flowing to the second stage of heating and deaerating.

Figure 2 illustrates a modification in that the high pressure and temperature condensate inlet 41 opens through the wall 23 for admitting the high pressure and temperature condensate into the chamber 24'. Thus the high pressure andA temperature condensate is introduced directly into the normal steam supply. The downtake pipe 48 and the neck 49 are functionally similar to the downtake pipe 26 and the neck 28, respectively. 'Ihe water flows from the downtake pipe 48 into a chamber 50 and ows therefrom through an annular passage 5| arranged concentrically of the annular passage 52 constituting an outlet for steam and high pressure and temperature condensate, in addition to steam flashed from the latter. Thus the streams of steam, water, high pressure and temperature condensate and steam flashed therefrom are caused to flow through the mixing passage 53 in the same manner as through the mixing passage 43 of Figure 1. The mixing passage 53 is of gradually increasing cross sectional area at 54 to function identically with the passage 4o of Figure 1.

In the present invention, the three streams emitted through the'passages 4|, 33, and 39 and the two passages 5| and 52 of Figure 2 are caused to flow through a confined mixing passage, which results in a thermal-compression action and causes a thorough mixing of the steam and water before they are projected into the lower pressure area for deaeration. By regulation of the relative areas of the passages 4|, 33, and 39 of Figure 1 and the passages 5| and 52 of Figure 2, the quantity of steam and water and high pressure and temperature condensate and steam flashed therefrom may be proportionately controlled and regulated to meet the conditions of operation under which the apparatus is to work, and in accordance with the final temperature of the water desired.

Both forms of the invention embody means whereby high pressure and temperature condensate and steam flashed therefrom may be .effectively utilized in a deaerator of the steam jet type and employing a multistage heating and deaerating structure. In the present invention, the high pressure and temperature condensate is admitted to the second stage of heating and deaeration and is directed into the mixing passage of this stage. The result is that the energy derived from this condensate may be effectively utilized as a scrubbing medium in the second stage under all conditions of operation. The high pressure and temperature condensate may be effectively employed to supplement deficiencies in the normal steam supply.

The general construction of the two forms is similar so that the same but primed reference characters are directed to the corresponding parts of Figure 2.

It will be understood that the invention is not to be limited vto the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In a water heating and deaerating system the method of utilizing high' temperature high pressure condensate auxiliary to the main water flow through the heater for augmenting the final heating and deaerating of the feed water, which consists in first primarily heating the Water by direct contact with steam, subsequently heating the water by a thorough mixing 'of the primarily heated water with steam, electing the mixed water and steam into a space of relatively low pressure to provide separation of the released gases from the heated water, and introducing the high temperature high pressure auxiliary condensate into the discharging ejecting mixed steam, and water prior to its discharge into the low pressure area.

2. In a water heating and deaerating system the l method of utilizing high temperature high pressure condensate auxiliary to the main water flow through the heater for augmenting the final heating and deaerating of the feed water, which consists in rst primarily heating the water by direct contact with steam, subsequently heating the water by a thorough mixing of the primarily heated water with steam, ejeoting the mixed water and steam into a space of relatively low pressure to provide separation of the released gases from the heated water, and introducing the high temperature high pressure auxiliary condensate into the discharging ejecting mixed steam, and water prior to its discharge into the low pressure area, and utilizing the inductive force of the high pressure high temperature auxiliary condensate for imparting velocity and heat energy into the discharging spray of mixed steam and water.

3. In a feedwater heating and deaerating system, the method of utilizing high temperature high pressure condensate auxiliary to the main Water flow through the heater for augmenting the nal heating and deaerating of the feed water which consists in passing the water together with steam through a confined passage for thoroughly mixing the steam and water, discharging the mixed steam and water into a space of relatively low pressure to separate out the released gases, and introducing the auxiliary high pressure high temperature condensate into the mixed steam and water during discharge thereof into the relatively low pressure space.

4. In a feedwater heating and deaerating system, the method of utilizing high temperature high pressure condensate auxiliary to the main water ow through the heater for augmenting the nal heating and deaerating of the feed Water which consists in passing the water together with steam through a confined passage for thoroughly mixing the steam and water, discharging the mixed steam and Water into a space of relatively low pressure to separate out the released gases, introducing the auxiliary high pressure high temperature condensate into the mixed steam and water during discharge thereof into the relatively low pressure space, and utilizing the inductive force of the high pressure high temperature auxiliary condensate for imparting velocity and heat energy into the discharging mixed steam and water.

5. In a water heating and deaerating apparatus, means forming a `combined mixing passage for steam and water, steam introducing means, water introducing means, means at the entrance of said passage for directing steam and water entering the passage in mixing flow relationship, a chamber under relatively low pressure, said passage discharging the mixed steam and water into said chamber, and means for mixing high temsaid'iixed steam and water during its discharge into said chamber, said auxiliary condensate mixl ing means comprising a wall structure spaced from said mixing passage and shaped to provide i i an induction passage opening into said mixing passage at a point where the inductive force of the highv pressure high temperature auxiliary condensate will impart velocity and heat energy tothe flowing mixed steam and Water.

n perature high pressure auxiliary condensate with v v form a water discharge passage anda mixing passage. an annular wall surrounding and spaced 6. In a Water heating and deaerating apparatus, I

means forming a combined mixing passage for n steam and water, steam introducing means, water introducing means, means at the entrance of said passage for directing steam and water entering the passage in mixing ow relationship, a cham-"1` ber under relatively low pressure, said passage discharging the mixed steam and water into said chambensaid mixing passage forming means including a water delivery pipe having anv annular 20 cupped flange at its discharge end, a steam inlet pipe surrounding and spaced from said Water inlet pipe and discharging steam into the cavity formed by said cupped flange, a combining cup surrounding said cupped flange and spaced to 'Y from said cup and extending thereabove to form a continuation of the mixing passage, said annular wall .shaped to provide a restricted passage portion directly outwardly of the outlet of the mixing passage in the cup, and means for delivering high temperature condensate into the space between the cup andv annular wall at a point in advance of the restricted passage portion.

JOSEPH F. SEBALD. REFERENCES CITED The following references are oi' record in the file of this patent: f y

UNITED STATES PATENTS 'Rohnn Mar. 2s, 1944 

